Method of making envelopes without side flaps



Dec. 10, 1940;

G. HOLMLUND METHOD OF MAKING ENVELOPES WITHOUT SIDE FLAPS Filed Sept. 9, 1959 Patented Dec. 10, 1-940 PATENT OFFiCE LIETHOD OF MAKING ENVELOPES W THbUT SIDE FLAPS a Gunnar Holmlund, Goteborg, Sweden, assignor to Maria (Majen) Lindgren, Goteborg, Sweden Application September 9, 1939, Serial No. 294,186 In Sweden December 15, 1937 4 Claims. (Cl. 93-35) It is known to manufacture envelopes from paper blanks having a rectangular centre panel,

to form the front'side of the envelope, and fiapsprojecting from the four edges of that rectangu- 5 lar panel, the bottom flap and the two side flaps being folded over and stuck together with gum arabic, to form the back of the envelope. The

fourth flap, which constitutes the closure flap of the envelope, is coated either with gum arabic 1 or with rubber solution; in the latter case a similar coating of rubber solution must be applied to the back of the envelope in such a way that the two rubber coatings come together (one on top of the other) when the envelope is closed. 15 A rubber coating of the kind referred to has the property of adhering to a similar coating of rubber when both coatings are dry, that is to say, when the solvent has evaporated from the rubber solution. On the other hand, these rubber coat- 0 ings will not adhere to surfaces which are not rubber coated. Gum arabic does not adhere to any other object when in a dry condition but sticks to other objects when moistened.

It is also known to make envelopes without side 25 fiaps by gluing a bottom or back flap to the front panel, with gum arabic, applied along the side edges.

According to the process which forms the subject matter of the present invention, a paper band fed from a roll .of paper, which has a transverse width sufllcient for two envelopes side by side, is provided on one surface with a longitudinal stripe or stripes of rubber solution, where the closure flaps are to be located, and, on the other side of the paper, with other longitudinal stripes of rubber solution, at tl ose places which register with the closure flap stripes when the envelopes are closed, that similar coatings of rubber solu- 40 tion are applied, on the first mentioned side of the paper, along lines which run transversely to the lengthof the band and which correspond to. the side edges of the envelopes that the applied stripes of rubber solution are dried, that the two 45 side edges of the paper band are then folded along the lines which are to form the bottom edges of the envelopes, that the paper band is next divided longitudinally along its middle line and that, finally, the envelopes are cut apart trans- 50 versely along their hitherto connected side edges.

A machine for carrying out the method of the, invention is illustrated diagrammatically in th accompanying drawing, in which:

Figure 1 shows the machine in plan view (as Figure 2 shows the same machine in side elevation.

Figure 3 shows the back of an produced on this machine. 3

A continuous web or band of paper I, the width 5 of which corresponds to the width of two unfolded envelope blanks is drawn off from a roll envelope as of paper 2 and brought under scoring wheels 3,

which produce folding lines or creases,as at 4, corresponding to the bottom edge 5 of the folded envelopes and further creases 6 for the folding of the top closure flap 8. The paper then passes under stamp rolls 9 which are so constructed and operated that they apply rubber solution in regularly spaced stripes Ill running transversely across the band i. In a later stage the envelopes are cut apart along the medial lines of the stripes l0. Thus the side edges ll of the envelopes (Fig. 3) correspond to the lines of severance and immediately adjacent these side edges ll there remain adhesive rubber coatings, half the width of the stripes l0.

After leaving the rolls 9 the paper band passes under a roll I2, which applies a longitudinal stripe l3 of rubber solution. This stripe I3 is subsequently parted longitudinally into two stripes which form the adhesive coatings of the closure flaps of the envelopes, as seen in Fig. 3. Next the paper band passes over rolls I4 (Fig. 2), which apply stripes l5 of rubber solution to the other side of the paper, near to the longitudinal edges of the band, as indicated in Fig. 1. Fig. 3 shows the,position of the stripe l5 in the finished envlope.

When the stripes of rubber solution have been applied at the requisite places on the moving band I the coatings mustbe dried. For this purpose the coated paper band may be directed upwards, as at i6, for drying in the open air or 40 in an apparatus (not shown) designed to facilitate the drying operation.

When the coatings have dried the paper band is brought down again, at H, andthence to a flap of the paper along the score lines or creases 4.

, In this operation the stripes 10 are, at the same time, folded upon themselves and thereby the side edges ll of the front panels and .the back fiaps of the envelopes are brought into adherent contact with each other. Firm adhesion may be ensured by a further pressing together of the envelopes thus folded. This can be accomplished by pairof rollers l9. At suitable points holes 20 are punched, by a stamp 2|, at the ends of the flaps '8, so that notches 22 are formed in the finished envelopes. These notches facilitate the insertion of a paper knife, when opening an envelope that has been scaled up. The paper band then passes under a cutting wheel 23, which cuts the paper along the longitudinal middle line, thereby separating the rows of envelopes at the edges of their closure flaps. Finally the two paper webs resulting from the longitudinal cutting of the band I are severed transversely by a knife 24, which thus cuts off two envelopes at a time, and the finished envelopes 26 fall into a tray 25.

The rolls I9, already referred to, exert a feeding action on the paper band I but this can be supplemented by the provision of additional feed rolls, for instance the rolls 21, receiving the downward run I! of the band may be operated as feed rolls. As supports for the band I and as counter roll-s for the scoring wheels 3 and the adhesive applying rolls 9 and I2, supporting rolls such as 28 may be used in any requisite number. Counter rolls 29 are arranged above the adhesive applying rolls I4. The adhesive rubber stripes I0,

I3 and I5 may each comprise several lines of adhesive instead of one line only. The scoring wheels 3 may be dispensed with as also may the stamps 2|. Adjacent the places where the rubber solution is to be applied cups or troughs 30, each containing a stock of solution are arranged and dipper rolls 3| raise the solution from these troughs in order that it may be transferred to the adhesive applying rolls.

The method described cannot be used with gum arabic, because inside the folding apparatus l8 there must be inserted, in known manner, a stationary metal band or the like to hold the paper down on to the inner angle of the apparatus I8, and a gum arabic solution could not be made to pass such metal band without being scraped off by the metal band which would smear it over the inside of the envelope, the whole interior of which would therefore get stuck together.

In place of the vertically reciprocating stamps 2|, rotating stamps may be used and may, if desired be located close to the adhesive applying roll 9. The holes 20 may serve for controlling the feed of the paper or the operation of the knife 24, so that the line of severance of the envelopes falls exactly in the middle of the holes 20w The rotating stamp may, for instance, be arranged on the same shaft as and between the rollers 9.

I claim:

1. The method of making envelopes without side flaps out of a continuous web or band of paper, which is coated with adhesive substance, cut and folded, consisting in providing a paper band fed from a roll of paper, which has a transverse width sufli'cient for two envelopes side by side, on one surface with a longitudinal stripe or stripes of rubber solution, where the closure flaps are to be located, and, on the other surface of the paper with other longitudinal stripes of rubber solution, at those places which will register with the closure flap stripes when the envelopes are closed, applying similar coatings of rubber solution on the first mentioned side of the paper along lines, which run transversely to the length of the band and which correspond to the side edges of the envelopes, drying the applied stripes .of rubber solution, then folding the two side edges of the paper band along the lines which are to form the bottom edges of the envelopes, di-

viding the paper band longitudinally along its middle line, and finally cutting envelopes apart transversely along their hitherto connected side edges.

2. The method of making envelopes without side fiaps out of a continuous web or band of paper, which is coated with adhesive substance, cut and folded, consisting in providing a paper band fed from a roll of paper, which has a transverse width sufficient for two envelopes side by side, on one surface with a longitudinal stripe or stripes of rubber solution, where the closure flaps are to be located, and, on the other surface of the paper with other longitudinal stripes of rubber solution, at those places which will register with the closure flap stripes when the envelopes are closed applying similar coatings of rubber solution on the first mentioned side of the paper along lines, which run transversely to the length of the band and which correspond to the side edges of the envelopes, drying the applied stripes of rubber solution, then folding the two side edges of the paper band along the lines which are to form the bottom edges of' the envelopes, dividing the paper band longitudinally along its middle line, finally cutting the envelopes apart transversely along their hitherto connected side edges, and providing the continuous paper band with longitudinal folding lines or creases corresponding to the bottom edges and the top edges of the envelopes in order to facilitate the folding over of the bottom flap portion andthe closure flap portion of the'said band.

3. The method of making envelopes without side flaps out of a continuous web or band of paper, which is coated with adhesive substance, cut and folded, consisting in providing a paper band fed from a roll of paper, which has a transverse width'sufiicient for two envelopes side by side, on one surface with a .longitudinal stripe or stripes of rubber solution, where the closure flaps are to be located, and, on the other surface of the paper with other longitudinal stripes of rubber solution, at those places which will register with the closure flap stripes when the envelopes are closed, applying similar coatings of rubber solution on the first mentioned side of the paper along lines, which run transversely to the length of the band and which correspond to the side edges of the envelopes, drying the applied stripes of rubber solution, then folding the two side edges of the paper band along the lines which are to form the bottom edges of the envelopes, di-

middle line, finally cutting the envelopes apart transversely along their hitherto connected side edges, and providing the paper, after the drying of the adhesive stripes thereon with perforations, such as punched holes, so located as to produce notches in the side edges of the closure flaps when the envelopes are cut apart.

4. The method of making envelopes without side flaps out of a continuous web or band of paper, which is coated with adhesive substance, cut and folded, consisting in providing a paper band fed from a roll of paper, which has a. transverse width sufficient for two envelopes side by side, on one surface with a longitudinal stripe or stripes of rubber solution, where the closure fiaps are to be located, and, on the other surface of the paper with other longitudinal stripes of rubber solution, at those places which will register with the closure flap stripes when the envelopes are closed, applying similar coatings of rubber solution on the first mentioned side of the paper 'viding the paper band longitudinally along its along lines, which run transversely to the length of the band and which correspond to the side edges of the envelopes, drying the applied stripesof rubber solution, then folding the two side edges of the paper band along the'llnes which are to form the bottom edges of the envelopes, dividing the paper band longitudinally along its middle line, finally cutting the envelopes apart transverselyalong their hitherto connected side edges, and providing the continuous paper band with longitudinal folding lines or creases corresponding to the bottom edges and the top edges of the envelopes in order to facilitate the folding over of the bottom flap portion and the closure flap portion of the said band and providing the paper,' after the drying of the adhesive stripes thereonwith perforations, such as punched holes, so located as to produce notches in the side edges of the closure flaps when the envelopes are cut apart.

GUNNAR. HOLMLUND. 

